package dao.impl;

import dao.UserDao;
import pojo.User;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class UserDaoImpl implements UserDao {
    @Override
    public List<User> findAll() {
        List<User> list = new ArrayList<>();
        // TODO
        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet resultSet = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            try {
                connection = DriverManager.getConnection(url, "root", "050420");
                // if(connection != null){
                System.out.println("连接成功");
                // }
                //3.sql
                String sql = "select * from user";
                //4.预编译sql
                preparedStatement = connection.prepareStatement(sql);
                resultSet = preparedStatement.executeQuery();
                //6.
                while (resultSet.next()) {
                    User U = new User();
                    U.setId(resultSet.getInt("id"));
                    U.setName(resultSet.getString("name"));
                    U.setPass(resultSet.getString("pass"));
                    list.add(U);
                }
                return list;
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } finally {

            try {
                if (resultSet != null) {
                    resultSet.close();
                }
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                throw new RuntimeException(e);
            }
        }
    }
}
                }
